; ************************************************
; TestRam tests external SRAM on the STK200
board
; Counts SRAM-positions by writing AAh and
55h
; in each position, verifies the content and
displays
; the MSB of the highest SRAM-adress on the
LEDs.
; ************************************************

; Explanation on the RAM access
; The MUX-IC 74HC573 and the SRAM
62256-70 have to be
; installed on the board.
; Port A is multiplexed adress bus
for the LSB adress and the
; data bus
; Port C is the upper adress bus
; Port D Bit
6 is /RD (Read) on the SRAM, Bit
7 is /WR (Write)
; Line ALE (Adress Latch Enable) is used, Pin 30 of the 8515
; If the whole external SRAM has been tested
ok, all LEDs are
; switched on except LED7. The highest adress then is
; 7FFFh, if a 32 kB SRAM is used.

; Main program

IN mp,MCUCR; Read MCU-Control-RegisterORI mp,0x80
; SetBit
7OUTMCUCR,mp
; If the SRAM used is slower than 70 ns and
therefore requires an
; additional WAIT-state, then Bit 6 has to
set additionally. The
; ORI command then must be ORI
mp,0xC0 to setbit
6, too.